Knockdown mold



E. ANDERSON Dec. 29, 1931.

IFIII u Patented Dec. 29, 1931 UNITED STATES PATENT, OFFICE EDWARDANDERSON, on DAYTON, orrro, ASSIGNOR, BY. MESNE ASSIGNMENTS, 'ro

SIMONDS W'ORDEN WHITE COMPANY, A CORPORATION OFQHIO KNocKpown MOLDApplication filed February 17, 1927. Serial No; 168,896;

This invention relates to molds forva} rious purposes, but moreparticularly to molds in which to form grinding wheels by pressure, andit is concerned with means'for knocking down the mold for the purpose ofreleasing the molded wheel. 7

As the objects and advantages of this invention will be more easily seenand appreciated after its construction has been de- 10 scribed, I shallproceed to describe it, refer-- ring to the accompanying drawings, inwhich,

Fig.1 is a View looking down ,on a mold constructed according to myplan, and

Fig. 2 is a vertical section of the mold, taken on line 22 of Fig. 1. Inthis View themold is standing upon what is understood to be the bed of apowerful press, while the ram of the press is bearingdown on the plungerwhich constitutes the top of the mold.

Fig. 3 is substantiallythe'same View as Fig. 2, save that the segments2020 have been removed from below the jacket 19 and placed on the upperedge of the jacket, for a purpose to be described presently. l

The molding chamber comprises the bottom plate 10, for forming one sideof the wheel, the body 11, which forms the periphery of the wheel, andthe top 12, that forms the side of the wheel opposite that formed by theplate 10. Preferably, the plate 10 is adapted to lie on the bed 13 of apress. As presses for this purpose are common in the art. the bed 13 andram 14 are merely shown symbolically, and are respresentative of thepress so far as it is necessary.

As is clearly shown in Fig. is formed with a plurality of segments, inthe present case four in number. These are numbered respectively 15, 16,17 and 18. There is no special merit in making the segment 18 smallerthan the others, except as a matter of convenience and economy inconstructing the body 11. As shown in the present case the interior ofthe body is cylindrical in form. The exterior is tapered toward theplate 10. In making the body, a solid ring is formed having the desiredcross section. The ring is so then cut into segments. As cutting thering 1, the body 11.

results in some'waste it becomes necessary to make up for the waste, andthis is done by cutting a small segment, such as 18, froma second ring.I As an alternative to this method the original ring may be cut towithin a small distance of the inner wall, say within one-eighth of aninch thereof, which uncut portion can then be easily broken. 'Thus thesegmentsare formed without any loss in the interior of the body, itbeing only necessary in reassembling the segments to put the fracturededges in contact with their respective mates.

For the purpose of holding the segments in place in bodily form, Iprovide a jacket 19, which is merely a ring, tapered on the inside toconform to the taper of the body 11.

This jacket restson segments 202Q, whereby it is supported at analtitude necessary to properly confine the segments of'the body 11. Inorder to avoid close fitting of the parts I form a rabbet on the edge ofthe plate 10, in which the lower edge'of the body rests. It isimmaterial, therefore, if because of the segments 2020 being a littletoo thick, the body is held up a little from the bottom of the rabbet inthe plate 10. 1

The plunger 12 extends above the body 11 enough to enable theram 14 ofthe press to bear on its upper end and compress the material 21 of whichthe wheel is formed. Preferably, the angularity of the taper on the body11 is such that as soon as the segments 2020 are removed from under itthe jacket will drop'to the bed of the press, thereby releasingthesemnents forming the body 11. But should the jacket adhere after thesupporting segments, 20-20 are withdrawn, the segments may be laid onthe upper edge of the jacket,-as in Fig. 3,and the ram then usedto.press the jacket free from the body. Obviously, very little pressurewill be needed for. this.

If desired a mandrel 22 set in the plate 10 may be used to form a'holein the wheel, the plunger '12 being then provided with the necessarybore.

' While my mold may be used for various purposes, and while when it isused for molding abrasive wheels various mixtures maybe employed,prepared and compacted in various ways, my mold is especially applicableto molding wheels by what is known as the dry press method. In thismethod the abrasive material, the clay and other materials which areused to bind the abrasive together, are mixed in a dry state, and thenslightly moistened, preferably with water. This mass is put into themold and pressed as above described. Afterward the wheels may be firedin the usual way.

It is not to be understood that the scope of my invention is limited tothe details of construction shown, as variations therein are possiblewithout departing from the spirit of the invention. For example, it isnot necessary to taper the outside of the body. Instead, a comparativelysmall area of the outside of each segment, preferably near its middle,may be made sufficiently prominent to engage the tapered inner wall ofthe j acket. This is so simple and easily understood that illustrationis unnecessary. Other modifications may also be made while remainingwithin the scope of my claims, which are as follows:

1. A mold for grinding wheels, comprising a bottom plate adapted to formone side of a wheel, a ring resting on said plate, whereby to form theperiphery of a wheel, said ring being formed of segments and taperedtoward said plate, a acket surrounding the ring and tapered interiorilyin conformity to the exterior of the ring, and supporting blocks for thejacket adapted to lie on a plane surface on which said bottom plate liesand support the jacket at an altitude enabling the jacket to hold thesegments in the form of a ring, said blocks being removable when it isdesired'to let the jacket down to release the segments.

2. A mold for grinding wheels, comprising a bottom plate adapted to formone side of a wheel, a in lying on said plate, whereby to form theperiphery of the wheel, said plate having a rabbet formed at itsperiphery in which the ring stands and whereby it is centered on theplate, the ring being tapered downward on the outside and composed of aplurality of segments; a jacket tapered on the inside to conform to theaforesaid taper, whereby the segments are held in position, and a pairof segments to lie on a plane surface on which said plate lies, andafford arest .for the jacket, supporting the acket at an altitudenecessary for holding the ring together, said segments being removableto let the jacket drop down and release the segments;

3. Apparatus for molding grinding wheels,

comprising a press with a bed and a movable ram; a mold comprising aplate adapted to form one side of a wheel, said plate lying upon saidbed, a ring whereby to form the periphery of the wheel, said ring beingformed with segments, a jacket surrounding and holding the segments inbodily form, the interior thereof being tapered, so when it is moveddownward with reference to the ring the segments are released, removablesegments interposed between said jacket and bed, thereby supporting thejacket in position enabling it to retain the ring in bodily form, and aplunger to stand on the material in the mold and form the side of thewheel opposite that formed by said plate, said plunger extending abovethe ring so it can be forced down by the ram.

4-. Apparatus for molding grinding wheels, comprising a press with a bedand a movable ram; a mold comprising a plate adapted to form one side ofa wheel, said plate lying upon said bed, a ring whereby to form theperiphery of the wheel, said ring being formed with segments, a jacketsurrounding and holding the segments in bodily form, the interiorthereof being tapered, so when it is moved downward with reference tothe ring the segments are released, removable segments interposedbetween said acket and bed, thereby supporting the j ackct in positionenabling it to retain the ring in bodily form, and a plunger to stand onthe material in the mold and form the side of the wheel opposite thatformed by said plate, said plunger extending above the ring so it can beforced down by the ram, said supporting'segments being adapted to belaid on the upper edge of the acket after being removed from below thejacket, so the ram can impinge on said segments and press the jacketdown should it adhere thereto after the operation of pressing the wheelis finished.

5. The method of molding a mass of material into a grinding wheel, whichmethod comprises putting said material into a mold whereby every desireddimension except one at once imparted to the mass, compacting the masstherein, thereby giving it the excepted dimension, then removing theportion of the mold which confines one side of the wheel and removing insections the portion of the mold which forms the perimeter of the wheel.

EDTVARD ANDERSON.

